Currency Examples

The following are real-world examples and brainstorming for marking up currency.

The Problem

The problem: how to explicitly specify a) that a figure/number relates to money; b) the currency of a stated figure; and c) the period in which that figure was current.

The currency sign cannot be used reliably since the same sign (or symbol) may represent more than one currency. eg. $ is used for many different dollars (USD, AUD, CAD...) and even other units like pesos.

The language of the page is not sufficient to define the currency of prices in the page:

More than one currency may be used by people who speak the same language.

The page may be written in one language and still quote prices/figures in a different country's currency.

Even if a country can be identified, more than one currency may be used in that country.

Converting currency figures is a reasonably easy problem to solve as indicated by the #Existing_Practices. However many automated conversion tools must make assumptions about the original figure's currency -- e.g. assuming a USD for all uses of $, or British Pounds for £ (which is also sometimes used to denote Lira).

Currency Changes

I wish to expand on one of the points mentioned above: there might be two or more currencies in the same country: e.g. in Romania

ROL - Romanian Lei [being phased out]

RON - Romanian New Lei

after Romania joins the EU, the RON will be replaced by Euro, too (not imediately, probably in 2-3 years)

Although the three letter code is different in this case, the currency is often given as Lei. There are other countries, where similar examples exist/existed. The two currencies might have an identical name, yet they have 2 very different meanings. Usually there is a difference of 3-4 orders of magnitude between the old currency and the new currency.
discoleo

Related problems

"Amounts" in arbitrary units is a bit harder and necessary for several applications.

For example, consider the work that has been done on a recipe microformat.

Though we haven't reached this problem yet in the research, I can see it
coming:

Say you wanted to create a "shopping list" application which you could tell which recipes you wanted to cook, and have it automatically total up all the various amounts of ingredients and give you the net amount of stuff you wanted to pick up.

It would need to be able to determine precise amounts/units of each ingredient. This might turn out to be like the currency problem, or it might be more complex, given the variety of units used in recipes, English vs. metric etc. That's a case that might need a microformat. We need more research and analysis to really justify it, but I can see it within the realm of probable possibility.

Use of currency amounts in tables

Representing currency amounts in a table format is very common. For instance, see Google Financials.

In this table representation, it does not make sense to provide the currency information for each cell. Instead, it should be provided once at the table, thead, tr, or th, level, and then a td may override the default value. This is very similar to the common practice of indicating the currency and formatting in plain english: "Numbers in thousands of dollars" in the table title/subtitle or legend.

The microformat for currency amounts should provide a way to represent a default currency for all children of a table, thead, tr, or th nodes.
The currency symbol/abbreviation should be optional in for elements defined as containing currency values/amounts, if a default currency has been defined in one of the ancestor elements.

"Like most Dickens novels, Bleak House was published in 19 monthly instalments, each containing 32 pages of text and two illustrations by Phiz. Each cost one shilling, except for the last, which was a double issue and cost two." Dates in the subsequent table range monthly from March 1852 - September 1853

"Despite the ending of cash payments for the rest of 1922, the main cause of Germany's inability to pay, the steady depreciation of the mark, was ongoing. Towards the end of the year it assumed a disastrous rapidity. On August 1, the US Dollar still stood at 643 Marks to the Dollar and the British Pound at 2,850 Marks to the Pound. But on September 5 the dollar had already risen to 1,440 Marks and the pound to 6,525 Marks, and in December the pound was worth between 30,000 and 40,000 marks and the dollar between 7,000 and 9,000."

"A barrel of Brent crude for February delivery came within range of $25 a barrel on Tuesday before slipping to $24.35, a closing price 48 cents above Friday's closing price of $23.87. In New York, the price of Nymex (New York Merchantile Exchange) crude reached $27.40 a barrel before settling at $27.40, a gain of 41 cents or 1.5% on the day. Nymex oil prices in 2000 averaged $30.20 a barrel, the highest level since 1983, and well above the 1999 average of $19.25. Traders also saw support for the oil price from the Opec basket of seven crude oils which stood at $21.75 a barrell on 29 December 2000. That was the seventh day the price stayed below a preferred range of $22-$28 a barrell. Under an Opec price stability measure, output will be cut by 500,000 barrels a day if the basket price stay below $22 for more than 10 days."